1. Field of the Invention
The present invention relates to a method and apparatus for forming an improved, reformed container bottom, with a result that the entire container is strengthened. Typically, this method and apparatus is used for reforming the bottoms of containers which have been formed of aluminum or other metal.
2. Related Art
U.S. Pat. No. 5,222,385 which is assigned to American National Can Company, Inc., (hereinafter referred to as the "ANC" patent) describes a method and apparatus for reforming the bottoms of drawn and ironed beverage containers. As stated in the ANC patent, which is herein incorporated by reference, the reforming of the can bottom results in an increase in the strength of the cans above that of prior art cans.
The apparatus of the ANC patent includes a jig for supporting a container along an outer annular wall of the container, and a reforming roller that is brought into engagement with a substantially vertical wall joining a central domed portion of the container to a convex U-shaped portion that defines a flange-like ridge on the bottom of the container. This apparatus requires the provision of spring biasing means to retract the rollers after their engagement with the container. Furthermore, separate and distinct means for moving the rollers in a radially outward direction to contact the can surface at the substantially vertical wall, and for driving the reforming rollers about an arcuate path during the reforming process, are required.